By Korina Lopez, USA TODAY

Grammer's all good: The Los Angeles-based singer/songwriter's career is finally heating up. The single Keep Your Head Up, off his self-titled debut album (out Tuesday), is keeping pace with the rising temperatures of summer. Already sitting at No. 8 on USA TODAY's hot adult-contemporary airplay chart, Keep's upbeat tempo and lyrics make it a perfect summer playlist contender. But for all of the tune's easygoing optimism, Grammer wrote it after a particularly difficult day. "After high school, I moved to Los Angeles to play music. I used to busk on the Promenade. One day, I'd been there for 12 hours and only made $10 or $15," the 27-year-old says. "I went back to my minivan, looked up at the sky and wondered what to do. Then I went home and wrote that song."

From busking to big time: Spending his days duking it out with other buskers for attention paid off. "In July 2009, my manager, Ben Singer, discovered me while I was performing on the 3rd Street Promenade," he says. "A few months after signing with him, I played him a song idea I had written, Keep Your Head Up." He sent the song around to several labels in April 2010, and that's when I signed with S-Curve Records. I feel very lucky to have them in my corner."

Written in the stars: Now, not only does he have a hit on his hands, but his words have inspired some big names. Last month, Taylor Swift tweeted about singing along to the song while in rehearsals for her Speak Now tour. Grammer is also getting ready to go on tour as the opener for Natasha Bedingfield this month and, later in the year, Colbie Caillat. "I'd love to work with Taylor Swift," he says. "Or sing the hook and play guitar alongside a hip-hop artist."

It's in the genes: Grammer credits his sunny disposition to his father, Grammy-nominated children's music artist Red Grammer. "Some of my earliest memories were of sitting backstage during my dad's shows," he says. "I grew up around artists who wrote music for a living, so I had a hands-on understanding of the business." The vibe was decidedly kid-friendly. "There were no drugs or hookers backstage," he jokes. "Just people singing sweet songs for children."

Branching off: His folk music background gave Grammer solid ground from which he grew his own sound. "I have three different places that I draw inspiration from. There's the guitar guys like Jason Mraz, John Mayer and Jack Johnson; piano influences like Coldplay, The Fray and OneRepublic," he says. "And then I really love how hip-hop creates complexity in words. I love Common, Lauryn Hill, Jay-Z and Kanye West. I try to make a smorgasbord of the three."

Hard lessons: Street performing was the only way to make money in his early days. "Busking is music boot camp," he says. "I'm just a guy with a guitar. So if I'm sitting next to a 4-year-old girl singing Janet Jackson songs on one side, and a father-son act doing acrobatics on the other, I had to learn how to get people to listen to me. The hardest times would be if someone would come up to me, and instead of giving me money, they'd ask me to keep it down because they're trying to eat. That hurt!"

The underbelly of busking: "It's all about getting a good spot, so everyone knows that being in front of McDonald's or Forever 21 is where you'll get the most traffic," he explains. "So the rule is you have to move every two hours. I'd get up at 7 a.m., get to the Promenade by 8. I had it timed so that by peak hours I had the good spots, and I would have a good day."

The wonders of technology: Grammer earned kudos at MTV's recent O Music Awards (which honor digital music) for his groundbreaking interactive video of Keep Your Head Up. "The basic idea was to have this guy keeping his head up, no matter what happened, so (Steve Greenberg, president of S-Curve Records) found this technology out of Israel that allowed readers to pick their own scenarios. It's like 'choose your own adventure,' " he says. "We shot 15 videos and it was just a brand-new way to experience video. I'm so glad I got to do it first." The Office's Rainn Wilson lends his star power to the music video. "I met Rainn through my old roommate, Devon Gundry. They'd written a book together, SoulPancake," Grammer says. "Rainn was so gracious, he'd been on The Office set all day and then spent eight hours shooting my video."

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